A simplest electric motor contains a drywall screw, one 1.5 V alkaline cell, six inches of plain copper wire and one small neodymium disk magnet. That’s it, you don’t need any other tools or supplies and in 30 seconds, an electric motor can be made that can run in excess of ten thousand RPM. Windell Oskay confirms this idea.
Brushed DC electric motor is the most common type of electric motor and they are found essentially in every object that moves or run on batteries. The specialty of the motor is that it attracts an electromagnet towards a permanent magnet and when the two are close enough, the polarity of the current is reversed, which now repels the permanent magnet.
Using this simple concept, the simplest motor called as the homopolar motor can actually make it real quick.
As you can see in the picture, as soon as the wire is touched to the side of the magnet, the electric circuit gets completed and the current flows out of the battery. In the lower part of the screw to the side part of the magnet to the wire, current continues to flow through the wire to the other end of the battery.
The magnetic field is parallel to the magnet’s axis of symmetry and the electric current flows through the magnet. The direction of the current is from the center of the magnet to the edge and hence it flows in the radial direction, which is perpendicular to the magnet’s axis of symmetry.
The concept based on the effect of a magnetic field that has the moving electric charges is applied here. A force is experienced, which is perpendicular to both the direction of movement and the magnetic field. The field is along the symmetry axis of the magnet while the charges move radically outward from that axis and the force is in the tangential direction, which allows the magnet to spin
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